Add Governance controlled burn extrinsic for native tokens (#892)

## Describe your changes

Added an extrinsic to burn native token based on a governance proposal


@serhii-temchenko @zktony We will do proper benchmarking of this
extrinsic later, and parachain withdraw is good enough to unblock its
voting now. Added a TODO for it.

pallets/thea-executor/src/lib.rs

@@ -49,7 +49,11 @@ pub mod pallet {
 	use frame_support::{
 		pallet_prelude::*,
 		sp_runtime::SaturatedConversion,
-		traits::{fungible::Mutate, fungibles::Inspect, tokens::Preservation},
+		traits::{
+			fungible::Mutate,
+			fungibles::Inspect,
+			tokens::{Fortitude, Precision, Preservation},
+		},
 		transactional,
 	};
 	use frame_system::pallet_prelude::*;
@@ -119,6 +123,8 @@ pub mod pallet {
 		type ExistentialDeposit: Get<u128>;
 		/// Para Id
 		type ParaId: Get<u32>;
+		/// Governance Origin
+		type GovernanceOrigin: EnsureOrigin<<Self as frame_system::Config>::RuntimeOrigin>;
 		/// Type representing the weight of this pallet
 		type WeightInfo: WeightInfo;
 	}
@@ -181,6 +187,8 @@ pub mod pallet {
 		TheaKeyUpdated(Network, u32),
 		/// Withdrawal Fee Set (NetworkId, Amount)
 		WithdrawalFeeSet(u8, u128),
+		/// Native Token Burn event
+		NativeTokenBurned(T::AccountId, u128),
 	}
 
 	// Errors inform users that something went wrong.
@@ -370,6 +378,30 @@ pub mod pallet {
 			Self::deposit_event(Event::<T>::AssetMetadataSet(metadata));
 			Ok(())
 		}
+
+		/// Burn Native tokens of an account
+		///
+		/// # Parameters
+		///
+		/// * `who`: AccountId
+		/// * `amount`: Amount of native tokens to burn.
+		#[pallet::call_index(5)]
+		#[pallet::weight(<T as Config>::WeightInfo::parachain_withdraw(1))] // TODO: Update the weights
+		pub fn burn_native_tokens(
+			origin: OriginFor<T>,
+			who: T::AccountId,
+			amount: u128,
+		) -> DispatchResult {
+			T::GovernanceOrigin::ensure_origin(origin)?;
+			let burned_amt = <T as Config>::Currency::burn_from(
+				&who,
+				amount.saturated_into(),
+				Precision::BestEffort,
+				Fortitude::Force,
+			)?;
+			Self::deposit_event(Event::<T>::NativeTokenBurned(who, burned_amt.saturated_into()));
+			Ok(())
+		}
 	}
 
 	impl<T: Config> Pallet<T> {

pallets/thea-executor/src/mock.rs

@@ -206,6 +206,7 @@ impl thea_executor::Config for Test {
 	type MultiAssetIdAdapter = AssetId;
 	type AssetBalanceAdapter = u128;
 	type ExistentialDeposit = ExistentialDeposit;
+	type GovernanceOrigin = EnsureRoot<Self::AccountId>;
 }
 
 impl<C> frame_system::offchain::SendTransactionTypes<C> for Test

pallets/thea-message-handler/src/mock.rs

@@ -204,6 +204,7 @@ impl thea_executor::Config for Test {
 	type WeightInfo = thea_executor::weights::WeightInfo<Test>;
 	type MultiAssetIdAdapter = AssetId;
 	type AssetBalanceAdapter = u128;
+	type GovernanceOrigin = EnsureRoot<u64>;
 	type ExistentialDeposit = ExistentialDeposit;
 }
 

pallets/thea/src/aggregator.rs

@@ -16,7 +16,7 @@
 // You should have received a copy of the GNU General Public License
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
 
-use crate::{resolver::Resolver, Config};
+use crate::{resolver::Resolver, Config, OutgoingMessages};
 use parity_scale_codec::{alloc::string::ToString, Decode, Encode};
 use scale_info::prelude::string::String;
 use sp_std::{marker::PhantomData, prelude::ToOwned, vec, vec::Vec};
@@ -55,18 +55,7 @@ impl<S: Decode, T: Config> AggregatorClient<S, T> {
 		match destination {
 			Destination::Solochain => {
 				// Get the outgoing message with nonce: `nonce` for network: `network`
-				let key = Self::create_solo_outgoing_message_key(nonce, network);
-				match Self::get_storage_at_latest_finalized_head::<Message>(
-					"solo_outgoing_message",
-					destination,
-					key,
-				) {
-					Ok(message) => message,
-					Err(err) => {
-						log::error!(target:"thea","Unable to get finalized solo head: {:?}",err);
-						None
-					},
-				}
+				<OutgoingMessages<T>>::get(network, nonce)
 			},
 			Destination::Parachain => {
 				// Get the outgoing message with nonce: `nonce` from network
@@ -90,23 +79,6 @@ impl<S: Decode, T: Config> AggregatorClient<S, T> {
 		}
 	}
 
-	/// Returns the encoded key for outgoing message for given nonce
-	/// # Parameters
-	/// * `nonce`: Nonce of the outgoing message
-	/// * `network`: Network of the outgoing message
-	/// # Returns
-	/// * `Vec<u8>`: Encoded key for outgoing message for given nonce
-	fn create_solo_outgoing_message_key(nonce: u64, network: Network) -> Vec<u8> {
-		let module_name = sp_io::hashing::twox_128(b"Thea");
-		let storage_prefix = sp_io::hashing::twox_128(b"OutgoingMessages");
-		let mut key = Vec::new();
-		key.append(&mut module_name.to_vec());
-		key.append(&mut storage_prefix.to_vec());
-		key.append(&mut network.encode());
-		key.append(&mut nonce.encode());
-		key
-	}
-
 	/// Returns the encoded key for outgoing message for given nonce for parachain
 	/// # Parameters
 	/// * `nonce`: Nonce of the outgoing message

pallets/thea/src/mock.rs

@@ -201,6 +201,7 @@ impl thea_executor::Config for Test {
 	type Swap = AssetConversion;
 	type MultiAssetIdAdapter = AssetId;
 	type AssetBalanceAdapter = u128;
+	type GovernanceOrigin = EnsureRoot<Self::AccountId>;
 	type ExistentialDeposit = ExistentialDeposit;
 }
 

runtimes/mainnet/src/lib.rs

@@ -122,7 +122,7 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
 	// and set impl_version to 0. If only runtime
 	// implementation changes and behavior does not, then leave spec_version as
 	// is and increment impl_version.
-	spec_version: 316,
+	spec_version: 317,
 	impl_version: 0,
 	apis: RUNTIME_API_VERSIONS,
 	transaction_version: 2,
@@ -1367,6 +1367,7 @@ impl thea_executor::Config for Runtime {
 	type Swap = AssetConversion;
 	type MultiAssetIdAdapter = AssetId;
 	type AssetBalanceAdapter = u128;
+	type GovernanceOrigin = EnsureRootOrHalfCouncil;
 	type ExistentialDeposit = ExistentialDeposit;
 }